1. Field of the Invention
The present invention relates to a rotary device of an apparatus for manufacturing a semiconductor device. More particularly, the present invention relates to a rotary head driven by a spindle in an apparatus for manufacturing a semiconductor device, and to the clamping structure that clamps the head to the spindle.
This is a counterpart of Korean Patent Application No. 2000-77823, filed Dec. 18, 2000, the contents of which are incorporated herein by reference in their entirety.
2. Description of the Related Art
A chemical-mechanical planarization or polishing (CMP) process removes material from the surface of wafers in the fabrication of integrated circuits of a semiconductor device. A conventional apparatus for performing a CMP process is disclosed in U.S. Pat. No. 5,702,292 to Brunelli et al.
Referring to FIG. 1, the conventional CMP apparatus includes a head 14 that picks up wafers using suction or surface tension. The head 14 is rotated by a spindle 12. The head 14 and spindle 12 are connected by a clamp 16.
The clamp 16 comprises a clamping frame and a bolt 18. The head 14 is connected to or disconnected from the spindle 12 by tightening or loosening the bolt 18 using a special tool such as a torque wrench. Thus, the operation of connecting or disconnecting the head 14 to or from the spindle 12 is complicated and takes time, which detracts from the efficiency at which the overall CMP process can be carried out.
Also, there is a problem in that particles are produced by the screw threads of the bolt 18 when the bolt is tightened or loosened. These particles fall onto the head 14 and then onto a polishing pad due to the vibration and rotation of the head 14 during the CMP process. Particles on the polishing pad may become a major cause of scratches on the surface of the wafers being polished.
It is therefore an object of the present invention to provide an improved apparatus for manufacturing a semiconductor device, in which a working head thereof can be connected to or disconnected from a spindle without using special tools, whereby the overall efficiency of the manufacturing process is enhanced.
It is another object of the present invention to provide an improved apparatus for manufacturing a semiconductor device, which produces a minimal amount of particles when a working head thereof is connected to or disconnected from a spindle, whereby such an operation does not produce manufacturing defects in the semiconductor device.
The present invention achieves these objects by providing a clamp that can be manipulated easily and with a simple motion to clamp the head to the spindle. The parts of the clamp generate little mechanical friction during the operation of connecting the head to or disconnecting the head from the spindle.
The clamp comprises an annular clamping frame encircling the outer circumference surfaces of the spindle and the head, a projection disposed on one end of the clamping frame, a lever pivotally supported by the other end of the clamping frame, and a fastener having one end pivotally connected to the lever and the other end configured to hook onto the projection.
The clamping frame comprises a first arcuate arm having a free end from which the projection protrudes, a second arcuate arm having a free end to which the lever is pivotally connected, and a hinge connecting the other ends of the first and second arms.
First, the annular clamping frame is positioned around and over the head and the spindle. The spindle and head may have outer circumferential flanges, and the clamping frame has a groove formed in the inner circumferential surface thereof. The flanges of the head and the spindle are received by the groove in the annular clamping frame.
The fastener is moved to a position at which it can be hooked onto (or unhooked from) the projection by rotating the lever in a first direction. Once the lever is hooked onto the projection, the lever is rotated in a second direction opposite to the first direction to force the projection in a direction that brings the free ends of the arms of the clamping frame together and thereby produces a clamping force that secures the spindle to the head.
The present invention also includes a safety mechanism for preventing the lever from being rotated by in the first direction a reaction force exerted thereon after the clamp has connected the head and spindle to one another. The safety mechanism includes a rod extending from the free end of the second arm and through the lever, a locking member mounted to the rod so as to be rotatable relative to the rod and slidable therealong, and at least one spring disposed on the rod and biasing the locking member so as to resiliently support the rod. Once the lever is closed, the rod engages the lever at an upper surface of the lever to prevent the lever from lifting off of the clamping frame and opening.